To ease plant preparation for use, it may be beneficial to create stock solutions of required chemicals days in advance of actual operation. Because certain chemical solutions equilibrate with air, they may perform better or worse with age. Using this set of experiments, it was to be determined whether an aluminum sulfate solution produces lower levels of effluent turbidity due to its age.
Matthew Higgin, Adam Salwen, and Christopher Guerrero
Accurate chemical dosing is important in water treatment plants to ensure optimal conditions for flocculation, sedimentation and disinfection of the treated water. The linear chemical dose controller uses laminar flow through a small diameter tube to create a linear relationship between head loss and chemical flow. The linear flow orifice meter then maintains a linear relationship between plant flow and water elevation. The linear relationships simplify chemical dosing for plant operators who may have a limited education. Our team is researching the upper-flow limit of the linear dose controller and developing innovative designs to increase the capacity of this system to function in plants with flow rates approaching and above 100 L/s. Furthermore, we are redesigning and simplifying the linear flow orifice meter algorithm to improve its precision and performance in the field.
Julie Silva
The Stock Tank Mixing team is required to improve the mixing process for the coagulant and disinfectant in the stock tank. Previous teams have developed the centrifugal pump design, which can mix the following chemicals: aluminum sulfate (alum), polyaluminum chloride (PACl) and calcium hypochlorite (Ca(ClO)3). This team decided to focus on the use of polyaluminum chloride. Due to its chemical properties, it is most likely the future coagulant of most AguaClara plants. The stock tank mixing team plans to design a mixing system that will improve operator ease in use of the mixer, achieve a truly homogeneous mixer, and be scalable to larger plants. The team will also create operator guidelines, and provide the operator with a verification of homogeneity.
Zeyu Yao, Saugat Ghimire
The Chemical Dose Controller is an important of component of a AguaClara plant. The CDC delivers the coagulant (Polyaluminum Chloride (PACl) or Aluminum sulfate (Alum)) to the influent water and disinfectant Calcium hypochloride to the effluent filtered water. The Chemical Dose Controller is a simple mechanical response device which maintains a linear relationship between the plant flow and the chemical dose. It consists of a calibrated lever arm which the operator can use to adjust the dose of the chemical based on the turbidity of the influent water. The Fall 2013 team started off by putting together three half size doser units for stacked rapid sand filters constructed in India. All the parts were shipped to India with a detailed instruction manual to aid the assembly. The dosers sent to India contained CPVC ball valves with fluoroelastomer seals that are more resistant to chlorine than the previously used PVC ball valves. The ball valves in all the AguaClara plants will now be replaced with these CPVC ball valves. Similarly, a lock-and lock container will now be used as the Constant Head tank for both chlorine and coagulant suspended with a chain and a turnbuckle for height adjustment. Although the lock-and-lock container degrades when in contact with chlorine, it is locally available and can be easily replaced. In addition to this, the design of a new half-size doser with single arm which only doses chlorine has been completed. A 3D sketchup file has been created and sent to Hancock Precision for fabrication. This new doser will primarily be used in low flow plants in India which only require chlorine delivery.
Zeyu Yao, Saugat Ghimire
The Chemical Dose Controller is an important of component of a AguaClara plant. The CDC delivers the coagulant (Polyaluminum Chloride (PACl) or Aluminum sulfate (Alum)) to the influnt water and disinfectant Calcium hypochloride to the effluent filtered water. The Chemical Dose Controller is a simple mechanical response device which maintains a linear relationship between the plant flow and the chemical dose. It consists of a calibrated lever arm which the operator can use to adjust the dose of the chemical based on the turbidity of the influent water. The Fall 2013 team started off by putting together three half size doser units for stacked rapid sand filters constructed in India. All the parts were shipped to India with a detailed instruction manual to aid the assembly. The dosers sent to India contained CPVC ball valves with flouroelastomer seals that are more resistant to cholrine than the previously used PVC ball valves. The ball valves in all the AguaClara plants will now be replaced with these CPVC ball valves. Similarly, a lock-and lock container will now be used as the Constant Head tank for both chlorine and coagulant suspended with a chain and a turnbuckle for height adjustment. Although the lock-and-lock container degrades when in contact with chlorine, it is locally available and can be easily replaced. In addition to this, the design of a new half-size doser with single arm which only doses chlorine has been completed. A 3D sketchup file has been created and sent to Hancock Precision for fabrication. This new doser will primarily be used in low flow plants in India which only require chlorine delivery
Fluoride Auto — Sarah Huang, Cindy Jin, Melissa Louie, Emily Yueh
The World Health Organization estimates that globally over one million people face adverse health consequences due to fluoride contamination of drinking water. The current state of fluoride removal technology is not suitable for water treatment plants, and continuous fluoride removal systems do not exist. The Fluoride team aims to develop a cheap and efficient apparatus to reduce ionic fluoride from contaminated water to a safe level. The Fall 2019 team hopes to redesign the flocculation process to optimize the adsorption of fluoride to polyaluminum chloride (PACl) coagulant and the sedimentation process to minimize PACl-fluoride complexes in the effluent, ultimately producing potable water.
